I don't think you can say that they are dangerous more than you can say that for example vegan diets are extreme and dangerous. They CAN be dangerous but there

I don't think you can say that they are dangerous more than you can say that for example vegan diets are extreme and dangerous. They CAN be dangerous but there are many who are successfully are eating that way and it is even a treatment against epilepsy seizures for some. https://www.epilepsy.com/learn/treating-seizures-and-epilepsy/dietary-therapies/ketogenic-diet#targetText=The%20%22classic%22%20ketogenic%20diet%20is%20a%20special%20high%2Dfat,carefully%20monitored%20by%20a%20dietitian.&targetText=Because%20the%20ketogenic%20diet%20is,become%20the%20primary%20fuel%20instead https://www.epilepsy.com/learn/treating-seizures-and-epileps....